An open study of the comparative efficacy and safety of caspofungin and liposomal amphotericin B in treating invasive fungal infections or febrile neutropenia in patients with haematological malignancy.

In a clinical non-trial setting, the efficacy and safety of caspofungin was compared with liposomal amphotericin B for the management of febrile neutropenia or invasive fungal infections in 73 episodes in patients with haematological malignancy. There were fewer episodes of drug toxicity with caspofungin than liposomal amphotericin B (58.3 vs 83.7 %, P=0.02). The favourable response rate for episodes of febrile neutropenia treated with caspofungin or liposomal amphotericin B was similar at 37.5 and 53.8 %, respectively, but more breakthrough fungal infections occurred with caspofungin than with liposomal amphotericin B (33.3 vs 0 %, P<0.05) in these patients who did not receive antifungal prophylaxis. None of four episodes of candidaemia or hepatosplenic candidiasis responded to caspofungin compared with three of four episodes treated with liposomal amphotericin B. Mortality was significantly higher with caspofungin treatment compared with liposomal amphotericin B (6/24 vs 2/49, P=0.01), mainly due to an excess of fungal infections (P=0.04). Caspofungin treatment was a significant independent predictor of mortality [odds ratio=7.6 (95 % confidence interval 1.2-45.5)] when sepsis severity, prolonged neutropenia and length of antifungal therapy were considered in a multiple logistic regression model. In clinical practice, there is a suggestion that caspofungin may not be as effective as liposomal amphotericin B in preventing breakthrough invasive fungal infections in febrile neutropenia or in preventing fungus-related deaths. Because of the potential biases in this observational study, these preliminary findings should be interpreted with caution and clarified with a larger cohort of patients.